This proposal is to investigate those processes which may be involved in transport of odorous substances to and away from receptor sites. Recent observations suggest that odors entering the vertebrate nose stimulate release of secretory granules from the sustentaclar cells, whereupon cilia on the olfactory receptor cells become active and beat in coordinated motion. The objectives of this study are to determine the role of odorous substances in stimulation of granule secretion and in initiating and coordinating ciliary activity; to develop methods for selectively blocking secretion and ciliary motion; to investigate the influence of changes in activity of these organelles on the responses of the receptor neurons measured electrophysiologically and on the responses of the organism measured behaviorally; to study the chemical interactions between olfactory stimuli and secretory granules. Measurements of organelle activity will use differential interference contrast microscopy, microcinematography, and light scattering. Electrophysiological measures will include electro-olfactograms and single cell action potentials recorded extracellularly from in vitro and in vivo preparations and summated olfactory nerve activity recorded in vivo. Autonomic conditioning and conditioned aversion techniques will be used to determine olfactory behavior changes induced by modifications of organelle activity. The feasibility of biochemically characterizing sustentacular cell granules using liquid chromatography and their affinities for odorous substances using equilibrium dialysis will be investigated.